Resting-state fMRI in patients with refractory epilepsy with and without drop attacks: exploring the connectivity of sensorimotor cortex.

OBJECTIVE: Patients with multifocal or generalized epilepsies manifesting with drop attacks have severe refractory seizures and significant cognitive and behavioural abnormalities. It is unclear to what extent these features relate to network abnormalities and how networks in sensorimotor cortex differ from those in patients with refractory focal epilepsies. Thus, in this study we sought to provide preliminary data on connectivity of sensorimotor cortex in patients with epileptic drop attacks, in comparison to patients with focal refractory epilepsies. METHODS: Resting-state fMRI (rs-fMRI) data was available for 5 patients with epileptic drop attacks and 15 with refractory focal epilepsies undergoing presurgical evaluation. Functional connectivity was analyzed with a seed-based protocol, with primary seeds placed at the precentral gyrus, the postcentral gyrus and the premotor cortex. For each seed, the subjects' timeseries were extracted and transformed to Z scores. Between-group analysis was then performed using the 3dttest+ + AFNI program. RESULTS: Two clusters of reduced connectivity in the group with drop attacks (DA group) in relation to those with focal epilepsies were found in the between-group analysis: the precentral seed showed reduced connectivity in the surrounding motor area, and the postcentral seed, reduced connectivity with the ipsilateral posterior cingulate gyrus. In the intra-group analyses, sensorimotor and premotor networks were abnormal in the DA group, whereas patients with focal epilepsies had the usual connectivity maps with each seed. CONCLUSION: This pilot study shows differences in the cerebral connectivity in the sensorimotor cortex of patients with generalized epilepsies and drop attacks which should be further explored to better understand the biological bases of the seizure generation and cognitive changes in these people.

Control of drop attacks with selective posterior callosotomy: Anatomical and prognostic data.

OBJECTIVE: In a previous proof of concept study, selective posterior callosotomy achieved similar degree of control of drop attacks as total callosotomy, while sparing prefrontal interconnectivity. The present study aims to confirm this finding in a larger cohort and to provide anatomical and prognostic data. METHODS: Fifty-one patients with refractory drop attacks had selective posterior callosotomy and prospective follow up for a mean of 6.4 years. Twenty-seven patients had post-operative magnetic resonance imaging (MRI) and 18 had tractography (DTI) of remaining callosal fibers. Pre and postoperative falls were quantified and correlated with demographic, clinical and imaging data. RESULTS: Mean monthly frequency of drop attacks had a 95 % reduction, from 297 before to 16 after the procedure. Forty- one patients (80 %) had either complete or greater than 90 % control of the epileptic falls. Age and duration of epilepsy at surgery correlated with outcome (p values, respectively, 0.042 and 0.005). Mean index of callosal section along the posterior-to-anterior axis was 53.5 %. Extending the posterior section anterior to the midbody of the corpus callosum did not correlate with seizure control (p 0.91), providing fibers interconnecting the primary motor (M1) and caudal supplementary motor areas (SMA) were sectioned. Only one patient had a notable surgical complication which resolved in two days. CONCLUSIONS: This level III cohort study with objective outcome assessment confirms that selective posterior callosotomy is safe and effective to control epileptic falls. Younger patients with smaller duration of epilepsy have better results. A posterior section contemplating the splenium, isthmus and posterior half of the body (posterior midbody) seems sufficient to achieve complete or almost complete control of drop attacks.

Selective Posterior Callosotomy for Treatment of Epileptic Drop Attacks: Video Documentation of the Surgical Technique: 2-Dimensional Operative Video.

This is a surgical technique video of selective posterior callosotomy (SPC), a novel surgical procedure to alleviate refractory epileptic drop attacks.1 Departing from traditional approaches aiming the anterior half or the entire callosum, SPC sections the posterior half of the callosum sparing prefrontal connectivity.1 Drop attacks are generalized epileptic seizures characterized by sudden falls.1 These seizures are often seen in diffuse brain pathology associated with generalized or multifocal epilepsies, whose electroencephalogram (EEG) "fingerprint" is bilaterally synchronous epileptic discharges.1 Sectioning the callosum to control drop attacks follows the rationale that the rapid synchronization of discharges between motor and premotor regions of both hemispheres is the basis.1 The standard approach to callosotomies always contemplated the anterior fibers of the callosum.2 Literature reports that anterior sections lead to unsatisfactory control of drop attacks, and results are improved when extended into a total callosotomy.2,3 This evidence coupled with diffusion tensor imaging (DTI) findings showing that motor and premotor fibers actually cross through posterior half of the callosum led us to hypothesize that selective section of the posterior half of the callosum would section all relevant motor fibers and control drop attacks to a similar extent to total callosotomies, with the advantage of sparing prefrontal interconnectivity3 and no split-brain syndrome. Both our series, one retrospective, followed by a new prospective study have confirmed SPC to be a safe procedure, leading to complete or greater than 90% control of epileptic falls in 85% of patients.1 The video presented here was recorded during a selective posterior callosotomy performed on a 13-yr-old girl who had hundreds of uncontrollable drop attacks per day. Falls were completely controlled with significant gains in psychomotor development and cognition, after 5 yr of follow-up. The patient provided signed consent to the surgical procedure, video acquisition, photo acquisition, and storage at operations, and the publication of this material.

Rare Case of Young Patient with Intraventricular Angiomatous Meningioma

Pediatricmeningiomas are rare and account for only 2.2% of the central nervous system (CNS) tumors. In this age group, they aremore frequently located in atypical sites, such as, mainly, the ventricular system, with a frequency of 8.8 to 13.6%. Adding this to the fact that the angiomatous subtype constitutes only 2.1% of allmeningiomas, the rarity of the case reported here is corroborated. We report a 17-year-old female patient diagnosed with intraventricular angiomatous meningioma; she underwent surgical resection of the tumor in the body and frontal horn of the right lateral ventricle, and there were no neurological sequelae. With a follow-up of 26 months, there was no recurrence and the patient had clinical stability. Intraventricular tumors usually have slow growth and reach a considerable size until they cause symptoms and then are diagnosed. In addition, the deep location of the tumor and its proximity to eloquent areas make these tumors a neurosurgical challenge. The angiomatous subtype, due to the presence of hypervascularization (consisting of > 50% of vascular components), may, in some cases, hinder surgical resection as well as be erroneously diagnosed. However, surgical treatment aimed at total resection of the lesion remains the conduct of choice in the case reported here, especially in patients in the first two decades of life, in which the use of radiation is avoided. Specifically when it comes to the surgery, we chose a transcalosal approach that allows a good transoperative visualization of the lesion when located in the body and frontal horn of the lateral ventricle.

Cefaleias: diagnóstico diferencial / Headache: differential diagnosis

Este trabalho tem por objetivo descrever um dos principais motivos de consultas médicas na atenção primária: cefaleia. Como investigar e quando suspeitar de uma doença mais grave. Quais as principais características e como realizar o diagnóstico diferencial entre as cefaleias primárias mais prevalentes.

This study aims to describe one of the most common complaints of medical attention in primary care: headache. How to investigate and when to suspect of a more serious disease. What are the main features and how to perform a differential diagnosis between the most prevalent primary headaches.

Diagnóstico por imagem do acidente vascular encefálico / Image diagnosis of stroke

Este artigo tem como objetivo apresentar um estudo sobre os achados radiológicos mais importantes na avaliação inicial do paciente com suspeita de acidente vascular encefálico.

This paper has the objective to present a study of the main radiologic findings in the initial evaluation of the patient with suspected stroke.